1. Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218, United States
2. Department of Chemistry and Nanoscience Centre, University of Copenhagen, Copenhagen 2100, Denmark
3. Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
4. Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
5. Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
6. Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
7. Howard Hughes Medical Institute, Baltimore, Maryland 21205, United States